If libpayload can't fit seabios' needs then it needs to change so that it can. It's not much of a library if seabios can't use it IMHO. This may boil down to making the build process more flexible. I don't know.
I wonder how much of the low 1M we should just take for our purposes. 1M is a tiny amount of memory, and there are already options for reserving the low 64k for "BIOSen" in the newer kernels, as well as scans for low memory corruption. Should we just mark all of low 1M as reserved and use it as needed?
ron